Method and apparatus for providing panorama image data

ABSTRACT

A method and an apparatus for providing panoramic image data by reconstructing frame images captured by a panoramic imaging apparatus, are disclosed. In reconstruction of images with multiple image layers, sizes of images reconstructed with an image layer or images to be used for a reconstruction are scaled. An image is selected by analyzing sharpness. A panoramic image is provided by combining selected image. According to the present invention, parts having unclear focal planes may be completely removed in a panoramic image and it is possible to provide an image including only with focused regions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage patent application of PCTInternational patent application No. PCT/KR2013/004367 (filed on May 16,2013) under 35 U.S.C. §371, which claims priority to Korean PatentApplication No. 10-2012-0051936 (filed on May 16, 2012), the teachingsof which are incorporated herein in their entireties by reference.

TECHNICAL FIELD

The present invention relates to a method and an apparatus for providingpanoramic image data, and more particularly, to a method and anapparatus for reconstructing images captured by a panoramicphotographing apparatus in accordance with a focal plane and combiningclear images after extracting the clear images from the reconstructedimages.

BACKGROUND ART

In a conventional panoramic auto-focusing algorithm, an image isprovided by selecting a focal plane of a specific interest region fortrajectory scan lengths with a frequency analysis and by linking thetrajectories. In this case, the reconstruction is performed by selectingone trajectory for each region if depths of the focal planes of upperregion/lower region (for example, the upper jaw/the lower jaw, theteeth/the roots of teeth)are different. Thus, there is a disadvantagethat focal points of images cannot be perfectly reconstructed. And, anerror is occurred in finding exact focal depth because an erroroccurrence possibility is high due to noise characteristics in an imagereconstruction with the frequency analysis.

DISCLOSURE Technical Problem

Therefore, the present invention is made to solve the problems of theconventional technology, and an object thereof is to form a consecutivecombined image by performing reconstruction after converting differentscan lengths of projection images depending on real positions of imagelayers into an identical scan length.

Also, another object of the present invention is to form a consecutivecombined image by dividing reconstructed respective images into uniformblocks, by performing noise removal and boundary (edge) detection, andby combining the selected images using interpolation.

Solution to Problem

According to an aspect of the present invention, there is provided amethod for providing a panoramic image, the method including steps of:(a) scaling sizes of images reconstructed with an image layer or imagesto be used for a reconstruction in consideration of a size of apredetermined reference image according to a reference image layer; (b)selecting an image in part or full representing a predetermined regionof interest clearly among scaled images; and (c) providing a panoramicimage with selected image.

The step of (a) includes: (a1) changing a size of the images to be usedfor the reconstruction to the same size of the reference image by usinginformation focus depths of a plurality of the image layers.

The method further includes: overlapping the images changed to have thesame size with the size of the reference image by intervalspredetermined according to the image layers.

The step of (b) includes: calculating scan lengths of the images to beused for the reconstruction; and changing the size of the images so thatthe calculated scan length corresponds to a predetermined base pixelvalue.

The step of (b) includes: removing noises in the scaled image with apredetermined algorithm; detecting boundary (edge) information fordetermining sharpness from the noise removed image; and selecting theimage in part or full representing the region of interest clearly.

It is preferable that the step of selecting the image includes:obtaining sums of information on the detected boundaries; and selectingan imaging having the maximum sum among the sums.

It is preferable that the selecting a clear image at the step of (b)includes: dividing the scaled images into a plurality of blocks andselecting the clear image among the divided block images.

It is preferable that the divided multiple blocks have specific regionsin block s overlapped with other block, and the clear image is selectedwith respect to the overlapped blocks.

It is preferable that at the step of (c), the panoramic image isprovided by interpolating the selecting images with respect to theoverlapped region for the overlapped blocks.

It is preferable that the step of (b) includes limiting range of imagelayers of analyzed image by setting a selected image layer as a seedvalue.

It is preferable that the image set as the seed value is an imagediscriminated as a clear image with respect to a predetermined specificregion of the reconstructed image.

It is preferable that the method of claim 11, wherein the step of (b)includes discriminating clear images with respect to regions adjacent tothe specific region as the specific region is a starting region.

It is preferable that the step of (a) includes reconstructing aplurality of projection image taken by a panoramic imaging apparatuswith a preset image layer.

It is preferable that the predetermined algorithm is a noise removalfilter including the typical Gaussian filter, the mean filter and thePoisson distribution conversion filter.

It is preferable that the step of detecting boundary (edge) informationmay be performed with the Sobel mask.

It is preferable that the images to be reconstructed are a plurality ofprojection images captured by a dental panoramic imaging apparatus, andthe predetermined specific region is a molar part.

According to another aspect of the present invention, there is providedan apparatus for providing a panoramic image includes: an image scalingunit configured to scale sizes of images reconstructed with an imagelayer or images to be used for a reconstruction in consideration of asize of a predetermined reference image according to a reference imagelayer; an image selection unit configured to select an image in part orfull representing a predetermined region of interest clearly amongscaled images; and an image providing unit configured to provide apanoramic image with selected image.

It is preferable that the image scaling unit includes a size change unitconfigured to change size of the images to be used for thereconstruction to the same size of the reference image by usinginformation focus depths of a plurality of the image layers.

It is preferable that the apparatus further includes an imageoverlapping unit configured to overlap the images changed to have thesame size with the size of the reference image by intervalspredetermined according to the image layers.

It is preferable that changing the size of the images includes:calculating scan lengths of the images to be used for thereconstruction; and changing the size of the images so that thecalculated scan length corresponds to a predetermined base pixel value.

It is preferable that the image selection unit includes: a noise removalunit configured to remove noises in the scaled image with apredetermined algorithm; a boundary detection unit configured to detectboundary (edge) information for determining sharpness from the noiseremoved image; and an image selection unit configured to select theimage in part or full representing the region of interest clearly.

It is preferable that the selection of selecting the image in the imageselection unit includes: dividing the scaled images into a plurality ofblocks and selecting the clear image among the divided block images.

It is preferable that the divided multiple blocks have specific regionsin block s overlapped with other block, and the clear image is selectedwith respect to the overlapped blocks.

It is preferable that the panoramic image is provided by interpolatingthe selecting images with respect to the overlapped region for theoverlapped blocks.

It is preferable that the image selection unit configured to set aselected image layer as a seed value to limit a range of image layers ofanalyzed image.

It is preferable that the image set as the seed value is an imagediscriminated as a clear image with respect to a predetermined specificregion of the reconstructed image.

It is preferable that the step of (b) includes discriminating clearimages with respect to regions adjacent to the specific region as thespecific region is a starting region.

According to another aspect of the present invention, there is provideda method for providing a panoramic image, the method includes steps of:scaling sizes of images reconstructed with an image layer or images tobe used for a reconstruction in consideration of a size of apredetermined reference image according to a reference image layer;removing noise of the images scaled to the same size by using apredetermined algorithm; detecting boundary (edge) information from thenoise removed image in order to determine sharpness; selecting an imagein part or full representing a predetermined region of interest clearlyamong scaled images; and providing a panoramic image by combining theselected image.

According to another aspect of the present invention, there is provideda computer-readable storage medium storing a program for performingsteps of: scaling sizes of images reconstructed with an image layer orimages to be used for a reconstruction in consideration of a size of apredetermined reference image according to a reference image layer;removing noise of the images scaled to the same size by using apredetermined algorithm; detecting boundary (edge) information from thenoise removed image in order to determine sharpness; selecting an imagein part or full representing a predetermined region of interest clearlyamong scaled images; and providing a panoramic image by combining theselected image.

Advantageous Effects

According to the present invention, a complete panoramic image is formedby reconstructing images captured by a panoramic photographing apparatusin a multiple focal points reconstruction manner, by removing noise ofrespective regions, obtained by dividing a plurality of focal pointimages into many regions, with a filter, and by using a combination ofoptimum focal planes after selecting the optimum focal planes with aboundary detection. Therefore, it is possible to remove unclear focalplane regions and to provide a image containing regions being in focusonly.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flow chart showing a method of providing panoramic images inaccordance with the present invention.

FIG. 2 is a diagram illustrating differences of scan plane lengthsdepending focus depths.

FIG. 3 is a diagram illustrating an example of converting the scan planelengths shown in FIG. 2 into an identical magnitude.

FIG. 4 is a flow chart showing detailed steps of selecting optimumimages with a method of providing panoramic image of FIG. 1.

FIG. 5 is an exemplary view showing selection of optimum images by usinga sum of boundary information in accordance with an embodiment of thepresent invention.

FIG. 6 is an example image divided into blocks for selecting optimumimages in accordance with an embodiment of the present invention.

FIG. 7 is an example image divided into overlapped blocks for selectingoptimum images in accordance with an embodiment of the presentinvention.

FIG. 8 is an exemplary view showing block phenomenon caused bydifferences of image layers in combining selected images in accordancewith an embodiment of the present invention.

FIG. 9 shows an exemplary view showing an interpolation for removing theblock phenomenon shown in FIG. 8 in accordance with an embodiment of thepresent invention.

FIG. 10 shows an example of limiting a selection range for optimumimages using one selected optimum image as a seed in accordance with anembodiment of the present invention.

FIG. 11 a block diagram showing an apparatus for providing images inaccordance with an embodiment of the present invention.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. In thefollowing description and drawings, like reference numerals are used torepresent identical or similar elements. Thus, repetitive descriptionsthereof will be omitted. When it is determined in the below descriptionthat specific description of known functions or configuration associatedwith the present invention unnecessarily makes the gist of the presentinvention vague, detailed description thereof will not be described.

FIG. 1 is a flow chart showing a method of providing panoramic images inaccordance with the present invention.

Referring to FIG. 1, a method for providing images in accordance with anembodiment of the present invention may include a step of scaling imagesso that reconstructed images may have same sizes S100, a step ofselecting clear images S200, and a step of providing a panoramic imagestep 300.

Step 100 of scaling images is a step of reconstructing images capturedby an imaging apparatus according to predetermined multiple image layersmore than one. The term image layer refers to a virtual segment or avirtual plane comprised of segments in a three dimensional (3D) spaceconstituted by focal points for defining or specifying a location of anobject (e.g., a dental arch including teeth in case of a dental image)to be captured. If the teeth actually intended to be captured correspondto a focal plane in a dental panoramic image, the resultant panoramicimage obtained may be clear. However, since the dental arrangements aredifferent from person to person, an actual dental layer of a patient isdifferent from an image layer defined by a panoramic image obtainingsystem. Such inconsistency between the actual dental layer and the imagelayer hinders visibility of the resultant panoramic image. Accordingly,in embodiments of the present invention, various image layers arepredefined and used taking into account variety in spatial distributionof an object.

In an embodiment of the present invention, image data may be frame-basedimage data obtained by a panoramic image obtaining apparatus, or areconstructed image data, e.g., a panoramic image as a final result.

In general, the panoramic image obtaining apparatus may include an X-raysource, an image sensor, and an image processing unit. The X-ray sourceirradiates X-rays while rotating around an object along certaintrajectories. For example, the X-ray source may irradiate X-rays whilerotating around the object along multiple image layer trajectories wherean area of interest of the object is located. The image sensor has acertain area, and receives X-rays and obtains images along multipleimage layer trajectories while moving with the X-ray source with theobject located between the two. The image processing unit receives theimages obtained from the image sensor and reconstructs the images forthe image layer trajectories into a panoramic image for a finaltrajectory. In an embodiment of the present invention, the image layertrajectories include dental arch area by means of a capturer.

At a step of scaling image S100, a size of a reconstructed image offrame images taken by the panoramic image obtaining apparatus or theframe image to be used for image reconstruction may be changed. In thescaling step S100, if the image is to be scaled is a reconstructedimage, it is preferable to change the size of the reconstructed image inconsideration of the size of a predetermined reference image. Thepre-determined reference image of this embodiment is preferably of animage reconstructed according to the corresponding image layer in thegeneral dental arch surface in consideration of the physical informationof the patient. It is preferable that the physical information mayinclude age, gender, height, and the weight. According to the presentembodiment, in the step of scaling the image S100, it is desirable toenlarge or reduce the size of the image to the same size as thereference image according to the image layer reflecting the physicalinformation. In the step of scaling the image S100, it is preferable tochange the sizes of the reconstructed image to a predetermined imagesize.

Referring to FIG. 2, when the image to be scaled in the step of scalingthe image S100 is a frame image will be described in detail. FIG. 2 is aflow chart showing the details of image reconstruction method accordingto an embodiment of the present invention. Referring to FIG. 2, the stepof scaling an image S100 may include a step of changing the size of theimage S110, and a step of overlapping the changed image S120.

In the step of changing the size of the image S110, a frame image takenby a panoramic imaging apparatus S112 is input, scan lengths accordingto a depth (focus depth) of the image layer on the frame image (S114) isinput, and the sizes of the images to be overlapped are changes to thesame size by using a scanning length S116.

According to the present embodiment, the depth refers to a distancebetween the panoramic imaging apparatus and the image layer, and it ispreferred to mean relative extents of protrusion of the image layers tothe dental arch photographed by the panoramic imaging apparatus.According to the present embodiment, the scan length means a relativelength in a region of interest when X-rays irradiated from the panoramicimaging apparatus pass through the region of interest to be examined. Asdepth of the image layer becomes deeper, the scan length of the X-ray isincreased.

Referring to FIG. 3, the scan length of a first scanning plane 15 of afirst image layer 10 is relatively shorter than the scan length of asecond image layer 20 of a second scan plane 25. Accordingly, it ispreferred to change the sizes of the images to the same size using thelengths of the scan surfaces according to the depth of the image layers,since the relative size of the region of interest in the image inputfrom the image sensor 30 varies depending on the image layer, even ifthe X-ray 5 irradiated from the panoramic imaging apparatus istransmitted through the same part of the region of interest. Accordingto this embodiment, the scan lengths in the image layers are calculatedbased on the width of X-rays irradiated by the panoramic imagingapparatus, and it is preferable to change the size of the image so thatthe scan length of the frame image for the region of interest to bescanned corresponds to a predetermined reference pixel value. It ispreferred that the predetermined reference pixel value in thisembodiment is a value to achieve the scan length of the region ofinterest in each image frame to a one pixel.

At a step of overlapping the changed image 120, the frame image to beoverlapped are selected from the images of which sizes are changed inthe step S110, the selected frame image are overlapped at apredetermined interval S122 and, and finally the overlapped scaled imageare generated S124. The predetermined interval means a degree ofoverlapping of the frame images according to a depth of the image layerwhen the frame images are overlapped by a graphics unit including apixel to produce a panoramic image. According to this embodiment, it ispreferable that the overlapping degree is reduced when the depth of theimage layer is relatively a longer, and the amount of overlap can bevariable in accordance with the original scan lengths of the frame imagewhen the frame image is scaled to the same size.

At a step of selecting an optimal image having optimum sharpness S200,the sharpness of the image reconstructed to have the same size in thestep of scaling S100 are analyzed, and an image having the best clarityis selected. The step of selecting the image S200 will be described morein detail with reference to FIG. 4. FIG. 4 is a flow chart showing theselection of the optimum image in detail with the panorama imageproviding method shown in FIG. 1.

The step of selecting the image S200 may include a step of removingnoises existing in the image S210, detecting a boundary from the imagewhere the noise is removed S220, and selecting an optimum image by usingthe detected boundary information S230.

Prior to the step of removing the noise S210, it is preferred to performa receiving step S202 for receiving the image scaled in the step ofscaling the image S100, a step of dividing the received image on ablock-by-block basis S204 and the step of removing the noise removalS210, and the step of detecting the boundary S220.

At the step of removing the noise in the image S210, any componentsother than the signal included in the image information are removed.Noise other than the component contained in the original image can becaused by external light or reflection of a signal, and the noiseincludes a meaningless signal of constant level which exists in thenatural world.

In all images, the noise component is always present due to a systemnoise of an apparatus and a X-ray distribution, and an image with anamplified noise it may be selected when the noise components is strongerthan the signal level of the image. In order to prevent this, apredetermined algorithm is applied to respective partial images. Thepredetermined algorithm may be a noise removal filter including thetypical

Gaussian filter, the mean filter and the Poisson distribution conversionfilter or the like in consideration of the X-ray distribution.

In the step for detecting the boundary information from the noiseremoved image S220, the boundary of the respective images, where thenoises are removed at the step of removing the noise S210, are detected.According to this embodiment, it is preferable that the boundary is aplane with which the region of interest (the dental arch) to be imagedcan be discriminated from background regions other than the region ofinterest in the panoramic imaging apparatus.

Detection of the boundary in this embodiment is preferably performedusing the Sobel mask. The boundary may exist in the changing point wherea brightness of the image varies from a high value to a low value orvice versa, and the shape, size and texture of an object may be shownwith the boundary. The detection of the boundary is acquiring theinformation of boundary of the image by using these attributes, and moredetail it is preferred to find pixels that correspond to the boundarysurface. The detection of the boundary is to detect the contrast orbrightness change rate based on the intensity. Preferably, a mask fordetecting the change rate according to this embodiment is Sobel mask.Sobel mask may detect a boundary surface in any direction, and is strongagainst noise, and it is sensitive in a diagonal direction of theboundary than the vertical or horizontal boundaries. It is preferablethat the size of the mask in this embodiment may be any one selectedfrom 3×3, 5×5, and 7×7, the larger the size of the mask is to increasethickness of the boundary and improve sharpness. In addition, the maskmay include a vertical or a horizontal mask, or a second orderderivative Laplacian mask.

In step of selecting the optimal image by using the detected boundaryinformation S230, the sharpness of the image may be analyzed by usingthe boundary information, and an image having optimum sharpness may beselected. In step of selecting the optimal image S230 according to thepresent embodiment, it is performed: a step 220 of summing the boundarysurface detected in the step of detecting the boundary surface S220, anda step of selecting the clear image S234 by using the sum of boundary.The sums of the boundaries are compared, and it is preferable to selectan image which has largest number of pixels at the boundaries as theoptimum image. The sum of the boundary refers to the relative number ofpixels in the detected boundary in the image. The step of selecting anoptimal image by using the detected boundary information will bedescribed in detail with reference to FIG. 5. FIG. 5 is an exemplaryview showing selection of optimum images by using a sum of boundaryinformation in accordance with an embodiment of the present invention.It is preferable that images 1 to 4 include a region of interest 50 inaccordance with this embodiment. According to this embodiment, the sumof the boundary detected by in image 4 is 160 while the sum of theboundary detected by in image 3 is 160. Thus, it is preferable to selectimage 3 unless the sums of the boundaries in images 1 and 2 do notexceed 200. It is desirable that sharpness represents degree of matchbetween the image layer and the shape of the object when an image isdisplayed most clearly in case that the image layer of a image coincideswith the geometry of the object. According to this embodiment, it ispreferable that the sharpness is the maximum when the sum of theboundary surface is maximum.

In step of selecting the image S200 according to the present embodiment,it is preferable to divide an image into a plurality of blocks and toanalyze the sharpness with respect to the divided images. Dividing theimage into blocks will be described with FIG. 6. FIG. 6 is an exampleimage divided into blocks for selecting optimum images in accordancewith an embodiment of the present invention. According to the presentembodiment, it is preferable to divide an image of a dental arch intoblocks 60 and to select an image having optimum sharpness for eachdivided image.

In accordance with another embodiment of the present invention, in thestep of selecting the image S200), as shown in FIG. 7, it is preferablethat images are divided into image blocks 60 a, 60 b and 60 coverlapping and sharing some parts of the image, and the sharpness ofthe divided images are analyzed. FIG. 7 is an example image divided intooverlapped blocks for selecting optimum images in accordance with anembodiment of the present invention. Three image blocks 60 a, 60 b and60 c divided with dot lines share a portion, and the sharpness of theoverlapping blocks are analyzed.

In a step of providing a panoramic image S300, the image selected in thestep of selecting the image S200 are combined to generate a singlecombined image. In generation of the combined image according to thepresent embodiment, it is preferred to divide the image into a pluralityof blocks and to combine the image selected as the optimum image for thedivided image. If the image is divided into blocks 60 a that do not haveoverlapping parts as shown in FIG. 6, the block phenomena maybegenerated in the combined image because the image layers correspondingto the respective blocks are different. With the block phenomenon,boundaries which do not exist in the actual object occur in someportions of the image. This will be described in detail with referenceto FIG. 8.

FIG. 8 is an exemplary view showing block phenomenon caused bydifferences of image layers in combining selected images in accordancewith an embodiment of the present invention. According to FIG. 8, theblock phenomenon was generated in an image of an apical portion 70 amongblocks denoted with solid lines. In order to remove the blockphenomenon, at the step of forming a combined image S300, it ispreferable to combine the optimum images selected at the step ofselecting images S200 after performing interpolation with the selectedimage. It is preferable that the images to be interpolated and combinedare the images which had divided into overlapped blocks sharing someparts of the image and selected by analyzing the sharpness of thedivided images. The interpolation may be performed to a specific regionshared by the image in the selected image by estimating a image layerfor the specific reason using the image layer of at least one imagesharing the specific region.

Referring to FIG. 9, FIG. 9 shows an exemplary view showing aninterpolation for removing the block phenomenon shown in FIG. 8 inaccordance with an embodiment of the present invention. According to theembodiment, it is preferable to estimate an image layer for a specificregion 80C shared by two blocks 80 a and 80 b shown in FIG. 9, by usingthe interpolation.

If it impossible to remove the noise completely in the step of removingthe nose S210 or the depths of image layers of adjacent images, amongthe images selected in the step of selecting the image S200, are changedrapidly, the image generated in the step of combining the images S300may include a region where a connection part is not continuous. In yetanother embodiment, at the step of generating the combined image S300,it is preferable that a range of the images analyzed at the step ofselecting images S200 may be limited with an image selected at the atthe step of selecting images S200 as a seed value (initial value).Referring to FIG. 10, an image set to as the seed value in thisembodiment is preferably an image selected as the optimum image for theblock having minimum noise. For images captured by a dental panoramicimaging apparatus, it is desirable to set an optimum image for a blockincluding posterior part 92 as the seed valued. Limitation of the rangeof the image, it is preferable to use the depth of the image set to theseed value. By using the depth, it is preferred to analyze images 96 forthe image layers having the depth within a predetermined range based onthe depth of the image set to as the seed value. The limited images arepreferably images which are neighboring the blocks 98 of the block ofthe image set as the seed value. Comprising sorting the images accordingto The present embodiment (S200) In the step of selecting the image S200in accordance with an embodiment, it is preferable to analyze thesharpness by extending the neighboring blocks repeatedly based on theblock of the image set as the seed value.

In a step of providing a panoramic image S300, the image generated bycombining the optimum image selected in the step of selecting the imageS200 is provided through a display unit 100.

According to this embodiment, it is preferable that in the step ofscaling the image S100 a plurality of projection image taken by apanoramic imaging apparatus are reconstructed along a preset imagelayer. The projection. image is an image formed with an X-ray received,by an image sensor when a panoramic imaging apparatus radiates theX-rays by rotating around an object along a specific trajectory, theradiated X-rays pass the object and the image sensor moving inassociation with the X-ray source through the subject receives theX-rays.

FIG. 11 a block diagram showing an apparatus for providing images inaccordance with an embodiment of the present invention.

The Image providing apparatus 1 according to the present invention mayinclude an image scaling unit 100 for scaling the reconstructed imagesof the image to have the same size, an image selection unit 200 forselecting a clear image, a panoramic image generation unit 300 forgenerating a panorama image with the use of the selected images, and adisplay unit 400 for providing users with the panoramic image.

An image scaling unit 100, as described above, is configured to scale areconstructed image of frame images taken by the panoramic imageobtaining apparatus or the frame image to be used for imagereconstruction. If the image to be scaled is the reconstructed image, asdescribed above, it is preferable to change the size of thereconstructed image in consideration of the size of a predeterminedreference image. If the image to be scaled is the frame image, accordingto this embodiment, the frame image taken by the panoramic imageobtaining apparatus are transferred and reconstructed with one or morepre-set multiple image layers. The image scaling unit 100 may include asize change unit 110 for changing the imaged. to be overlapped and anoverlapping unit 120 for overlapping the change image.

The image size changing unit 110 may receive the frame image taken bythe panoramic image obtaining apparatus (S112) and the scan lengthaccording to the depth of the image layer on the frame image (focusdepth) (S1114) and may change toe size of the images to be overlappedare changed with the scan. length. As mentioned above, the sizes of theimages to be overlapped may be changed to the same size by using shescan length depending on the focus depth of the image layer. The imageoverlapping unit 120 may select the frame images to be overlapped amongthe images changed at the step of scaling S110 as mentioned above,overlap the selected frame images by a predetermined interval S122 andfinally generate an overlapped and scaled image S124.

The image selection unit 200 may include a noise removing unit 210, aboundary detecting unit 220 for detecting a boundary in she image fromwhich the noise has been removed, and image discriminating unit 230configured to discriminate the optimum image by using the information onthe boundary. The image selection unit 200 may select the image havingoptimum sharpness by analyzing the sharpness of the image scaled in theimage scaling unit 100.

As described above, the noise removing unit 21.0 is preferable toreceive images scaled in the scaling unit 100 (S202) and to divide thereceived image on a block-by-block basis (3204) prior to removing thenoise (S210), and thereafter the noise removing unit 210 may perform thenoise remove (S210) and the boundary detection (S220).

The noise removing unit 210 may remove the components other than thesignal included in the image information (S210).

The boundary detecting unit 220 may detect the boundary with respect tothe image after removing noise by the noise removing unit 210 (S220).The image discriminating unit 230 may analyze the sharpness of the imageby using the boundary information detected by the boundary detectingunit 220, and select an image having optimum sharpness (S230).

The panorama image generation unit 300 may generate a combined image(S300) by combining the clear image selected in the image selection unit200 as described above.

The display unit 400 may receive the image generated by the imagegeneration unit 300 and display the combined image to the user.

The method for providing panoramic image according to the embodiments ofthe present invention may be embodied as computer-readable codes on acomputer-readable recording medium. The computer-readable recordingmedium is any data storage device that can store data which can bethereafter read by a computer system.

For example, the computer-readable recording medium may include a ReadOnly Memory (ROM), a Random Access Memory (RAM), a Compact Disc ROM(CD-ROM), a magnetic tape, a floppy disk, an optical data storagedevice, etc., and the computer readable recording medium can also bedistributed over network coupled computer systems so that the computerreadable code is stored and executed in a distributed fashion.Furthermore, functional programs, codes and code segments to implementthe embodiments of the present invention may be readily inferred byprogrammers in the art.

The invention claimed is:
 1. A method for providing a panoramic image by an apparatus including at least one memory configured to store image data, at least one processor configured to perform operations for providing a panoramic image using the stored image data, and a communication circuit configured to communicate with other entities through a communication network, the method comprising: (a) scaling sizes of images reconstructed with an image layer or images to be used for a reconstruction in consideration of a size of a predetermined reference image according to a reference image layer; (b) selecting an image in part or full representing a predetermined region of interest clearly among scaled images; and (c) providing a panoramic image with selected image, wherein the step of (b) selecting includes limiting range of image layers of analyzed image by setting a selected image layer as a seed value, wherein the image set as the seed value is an image discriminated as a clear image with respect to a predetermined specific region of the reconstructed image, and wherein the step of (b) selecting includes discriminating clear images with respect to regions adjacent to the specific region as the specific region is a starting region.
 2. The method of claim 1, wherein step of (a) includes: (a1) changing a size of the images to be used for the reconstruction to the same size of the reference image by using information focus depths of a plurality of the image layers.
 3. The method of claim 2, wherein further comprising: overlapping the images changed to have the same size with the size of the reference image by intervals predetermined according to the image layers.
 4. The method of claim 2, wherein the step of (b) includes: calculating scan lengths of the images to be used for the reconstruction; and changing the size of the images so that the calculated scan length corresponds to a predetermined base pixel value.
 5. The method of claim 1, wherein the step of (b) includes: removing noises in the scaled image with a predetermined algorithm; detecting boundary information for determining sharpness from the noise removed image; and selecting the image in part or full representing the region of interest clearly.
 6. The method of claim 5, wherein the step of selecting the image includes: obtaining sums of information on the detected boundaries; and selecting an imaging having the maximum sum among the sums.
 7. The method of claim 1, wherein selecting a clear image at the step of (b) includes: dividing the scaled images into a plurality of blocks and selecting the clear image among the divided block images.
 8. The method of claim 7, wherein the divided multiple blocks have specific regions in blocks overlapped with other block, and the clear image is selected with respect to the overlapped blocks.
 9. The method of claim 8, wherein at the step of (c), the panoramic image is provided by interpolating the selecting images with respect to the overlapped region for the overlapped blocks.
 10. The method of claim 1, wherein the step of (b) includes limiting range of image layers of analyzed image by setting a selected image layer as a seed value.
 11. The method of claim 10, the image set as the seed value is an image discriminated as a clear image with respect to a predetermined specific region of the reconstructed image.
 12. The method of claim 1, wherein the step of (a) includes reconstructing a plurality of projection image taken by a panoramic imaging apparatus with a preset image layer.
 13. An apparatus for providing a panoramic image, the apparatus comprising: at least one memory configured to store image data; at least one processor configured to perform operations to provide a panoramic image; and a communication circuit configured to communicate with other entities through a communication network, wherein the at least one processor comprises: an image scaling unit configured to perform operations for scaling sizes of images reconstructed with an image layer or images to be used for a reconstruction in consideration of a size of a predetermined reference image according to a reference image layer; an image selection unit configured to perform operations for selecting an image in part or full representing a predetermined region of interest clearly among scaled images; and an image providing unit configured to perform operations for providing a panoramic image with selected image, wherein the image selection unit is configured to set a selected image layer as a seed value to limit a range of image layers of analyzed image, wherein the image set as the seed value is an image discriminated as a clear image with respect to a predetermined specific region of the reconstructed image, and wherein the image selection unit is configured to further perform operations for discriminating clear images with respect to regions adjacent to the specific region as the specific region is a starting region.
 14. The apparatus of claim 13, wherein the image scaling unit includes a size change unit configured to change size of the images to be used for the reconstruction to the same size of the reference image by using information focus depths of a plurality of the image layers.
 15. The apparatus of claim 14, wherein the at least one processor further comprises an image overlapping unit configured to overlap the images changed to have the same size with the size of the reference image by intervals predetermined according to the image layers.
 16. The apparatus of claim 14, wherein the size change unit is configured to perform operations of: calculating scan lengths of the images to be used for the reconstruction; and changing the size of the images so that the calculated scan length corresponds to a predetermined base pixel value.
 17. The apparatus of claim 13, wherein the image selection unit includes: a noise removal unit configured to remove noises in the scaled image with a predetermined algorithm; a boundary detection unit configured to detect boundary (edge) information for determining sharpness from the noise removed image; and an image selection unit configured to select the image in part or full representing the region of interest clearly.
 18. The apparatus of claim 13, wherein the image selection unit is configured to perform operations of: dividing the scaled images into a plurality of blocks; and selecting the clear image among the divided block images.
 19. The apparatus of claim 18, wherein the divided multiple blocks have specific regions in blocks overlapped with other block, and the clear image is selected with respect to the overlapped blocks.
 20. The apparatus of claim 19, wherein the panoramic image is provided by interpolating the selecting images with respect to the overlapped region for the overlapped blocks.
 21. The apparatus of claim 13, wherein the image selection unit is configured to set a selected image layer as a seed value to limit a range of image layers of analyzed image.
 22. The apparatus of claim 21, the image set as the seed value is an image discriminated as a clear image with respect to a predetermined specific region of the reconstructed image. 